1 | /* $OpenBSD: readpassphrase.c,v 1.23 2010/05/14 13:30:34 millert Exp $ */ |
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2 | |
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3 | /* |
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4 | * Copyright (c) 2000-2002, 2007, 2010 |
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5 | * Todd C. Miller <Todd.Miller@courtesan.com> |
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6 | * |
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7 | * Permission to use, copy, modify, and distribute this software for any |
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8 | * purpose with or without fee is hereby granted, provided that the above |
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9 | * copyright notice and this permission notice appear in all copies. |
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10 | * |
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11 | * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
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12 | * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
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13 | * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR |
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14 | * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
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15 | * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
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16 | * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF |
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17 | * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
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18 | * |
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19 | * Sponsored in part by the Defense Advanced Research Projects |
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20 | * Agency (DARPA) and Air Force Research Laboratory, Air Force |
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21 | * Materiel Command, USAF, under agreement number F39502-99-1-0512. |
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22 | */ |
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23 | |
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24 | /* OPENBSD ORIGINAL: lib/libc/gen/readpassphrase.c */ |
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25 | |
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26 | /** |
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27 | * Tom Carroll <thomas.carroll@pnnl.gov> |
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28 | * |
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29 | * Properly handled tcsetattr and SIGTTOU |
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30 | */ |
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31 | |
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32 | #ifndef HAVE_READPASSPHRASE |
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33 | |
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34 | #include <ctype.h> |
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35 | #include <errno.h> |
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36 | #include <fcntl.h> |
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37 | #ifdef HAVE_PATHS_H |
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38 | # include <paths.h> |
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39 | #endif |
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40 | #include <signal.h> |
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41 | #include <string.h> |
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42 | #include <termios.h> |
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43 | #include <unistd.h> |
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44 | #include "compat/readpassphrase.h" |
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45 | |
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46 | #ifndef TCSASOFT |
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47 | # define TCSASOFT 0 |
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48 | #endif |
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49 | |
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50 | #ifndef NSIG |
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51 | # ifdef _NSIG |
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52 | # define NSIG _NSIG |
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53 | # else |
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54 | # define NSIG 128 |
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55 | # endif |
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56 | #endif |
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57 | |
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58 | static volatile sig_atomic_t signo[NSIG]; |
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59 | |
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60 | static void handler(int); |
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61 | |
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62 | char * |
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63 | readpassphrase(const char *prompt, char *buf, size_t bufsiz, int flags) |
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64 | { |
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65 | ssize_t tmp; |
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66 | ssize_t nr; |
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67 | int input, output, save_errno, i, need_restart; |
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68 | char ch, *p, *end; |
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69 | struct termios term, oterm; |
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70 | struct sigaction sa, savealrm, saveint, savehup, savequit, saveterm; |
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71 | struct sigaction savetstp, savettin, savettou, savepipe; |
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72 | |
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73 | /* I suppose we could alloc on demand in this case (XXX). */ |
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74 | if (bufsiz == 0) { |
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75 | errno = EINVAL; |
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76 | return(NULL); |
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77 | } |
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78 | |
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79 | restart: |
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80 | for (i = 0; i < NSIG; i++) |
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81 | signo[i] = 0; |
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82 | nr = -1; |
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83 | save_errno = 0; |
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84 | need_restart = 0; |
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85 | /* |
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86 | * Read and write to /dev/tty if available. If not, read from |
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87 | * stdin and write to stderr unless a tty is required. |
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88 | */ |
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89 | if ((flags & RPP_STDIN) || |
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90 | (input = output = open(_PATH_TTY, O_RDWR)) == -1) { |
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91 | if (flags & RPP_REQUIRE_TTY) { |
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92 | errno = ENOTTY; |
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93 | return(NULL); |
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94 | } |
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95 | input = STDIN_FILENO; |
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96 | output = STDERR_FILENO; |
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97 | } |
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98 | |
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99 | /* |
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100 | * Turn off echo if possible. |
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101 | * If we are using a tty but are not the foreground pgrp this will |
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102 | * generate SIGTTOU, so do it *before* installing the signal handlers. |
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103 | */ |
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104 | if (input != STDIN_FILENO && tcgetattr(input, &oterm) == 0) { |
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105 | memcpy(&term, &oterm, sizeof(term)); |
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106 | if (!(flags & RPP_ECHO_ON)) |
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107 | term.c_lflag &= ~(ECHO | ECHONL); |
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108 | #ifdef VSTATUS |
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109 | if (term.c_cc[VSTATUS] != _POSIX_VDISABLE) |
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110 | term.c_cc[VSTATUS] = _POSIX_VDISABLE; |
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111 | #endif |
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112 | (void)tcsetattr(input, TCSAFLUSH|TCSASOFT, &term); |
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113 | } else { |
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114 | memset(&term, 0, sizeof(term)); |
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115 | term.c_lflag |= ECHO; |
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116 | memset(&oterm, 0, sizeof(oterm)); |
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117 | oterm.c_lflag |= ECHO; |
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118 | } |
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119 | |
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120 | /* |
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121 | * Catch signals that would otherwise cause the user to end |
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122 | * up with echo turned off in the shell. Don't worry about |
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123 | * things like SIGXCPU and SIGVTALRM for now. |
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124 | */ |
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125 | sigemptyset(&sa.sa_mask); |
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126 | sa.sa_flags = 0; /* don't restart system calls */ |
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127 | sa.sa_handler = handler; |
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128 | (void)sigaction(SIGALRM, &sa, &savealrm); |
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129 | (void)sigaction(SIGHUP, &sa, &savehup); |
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130 | (void)sigaction(SIGINT, &sa, &saveint); |
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131 | (void)sigaction(SIGPIPE, &sa, &savepipe); |
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132 | (void)sigaction(SIGQUIT, &sa, &savequit); |
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133 | (void)sigaction(SIGTERM, &sa, &saveterm); |
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134 | (void)sigaction(SIGTSTP, &sa, &savetstp); |
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135 | (void)sigaction(SIGTTIN, &sa, &savettin); |
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136 | (void)sigaction(SIGTTOU, &sa, &savettou); |
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137 | |
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138 | if (!(flags & RPP_STDIN)) |
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139 | tmp=write(output, prompt, strlen(prompt)); |
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140 | end = buf + bufsiz - 1; |
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141 | p = buf; |
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142 | while ((nr = read(input, &ch, 1)) == 1 && ch != '\n' && ch != '\r') { |
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143 | if (p < end) { |
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144 | if ((flags & RPP_SEVENBIT)) |
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145 | ch &= 0x7f; |
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146 | if (isalpha(ch)) { |
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147 | if ((flags & RPP_FORCELOWER)) |
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148 | ch = (char)tolower(ch); |
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149 | if ((flags & RPP_FORCEUPPER)) |
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150 | ch = (char)toupper(ch); |
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151 | } |
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152 | *p++ = ch; |
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153 | } |
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154 | } |
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155 | *p = '\0'; |
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156 | save_errno = errno; |
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157 | if (!(term.c_lflag & ECHO)) |
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158 | tmp=write(output, "\n", 1); |
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159 | |
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160 | /* Restore old terminal settings and signals. */ |
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161 | if (memcmp(&term, &oterm, sizeof(term)) != 0) { |
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162 | sigset_t ttou_sigset, old_sigset; |
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163 | sigemptyset(&ttou_sigset); |
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164 | sigaddset(&ttou_sigset, SIGTTOU); |
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165 | sigprocmask(SIG_BLOCK, &ttou_sigset, &old_sigset); |
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166 | while (tcsetattr(input, TCSAFLUSH|TCSASOFT, &oterm) == -1 && |
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167 | errno == EINTR) |
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168 | continue; |
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169 | sigprocmask(SIG_SETMASK, &old_sigset, NULL); |
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170 | } |
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171 | (void)sigaction(SIGALRM, &savealrm, NULL); |
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172 | (void)sigaction(SIGHUP, &savehup, NULL); |
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173 | (void)sigaction(SIGINT, &saveint, NULL); |
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174 | (void)sigaction(SIGQUIT, &savequit, NULL); |
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175 | (void)sigaction(SIGPIPE, &savepipe, NULL); |
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176 | (void)sigaction(SIGTERM, &saveterm, NULL); |
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177 | (void)sigaction(SIGTSTP, &savetstp, NULL); |
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178 | (void)sigaction(SIGTTIN, &savettin, NULL); |
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179 | (void)sigaction(SIGTTOU, &savettou, NULL); |
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180 | if (input != STDIN_FILENO) |
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181 | (void)close(input); |
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182 | |
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183 | /* |
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184 | * If we were interrupted by a signal, resend it to ourselves |
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185 | * now that we have restored the signal handlers. |
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186 | */ |
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187 | for (i = 0; i < NSIG; i++) { |
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188 | if (signo[i]) { |
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189 | kill(getpid(), i); |
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190 | switch (i) { |
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191 | case SIGTSTP: |
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192 | case SIGTTIN: |
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193 | case SIGTTOU: |
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194 | need_restart = 1; |
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195 | } |
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196 | } |
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197 | } |
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198 | if (need_restart) |
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199 | goto restart; |
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200 | |
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201 | return(nr == -1 ? errno = save_errno, NULL : buf); |
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202 | } |
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203 | |
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204 | static void handler(int s) |
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205 | { |
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206 | |
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207 | signo[s] = 1; |
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208 | } |
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209 | |
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210 | #endif /* ! HAVE_READPASSPHRASE */ |
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